Late Saturday, Hamas leaders met with their counterparts from the violent Islamic Jihad (search) and other radical factions, where they repeated their rejection of the call to stop attacks against Israel.

He said the groups did not change their earlier view that they would not stop attacks until Israel ends its occupation of Palestinian lands. Neither group accepts the idea of a Jewish state in the Mideast.

After the meeting, Islamic Jihad official Mohammed Hindi told The Associated Press, "No changes have been made in the previous position concerning the cease-fire."

Reflecting the continuing tension, Israel reimposed a closure on the West Bank (search), banning Palestinians from entering Israel except in humanitarian cases. The closure took effect at midnight Saturday "due to a government decision and serious security alerts," a military statement said.

Israeli security sources have noted dozens of warnings of potential terror attacks, originating from the West Bank, in recent days. Israel lifted its last closure just a week ago after a meeting between Palestinian Prime Minister Mahmoud Abbas (search) and Israeli Prime Minister Ariel Sharon (search).

As part of the U.S.-backed "road map" to Mideast peace, the Palestinians have to disarm and dismantle militant groups that have killed hundreds of Israelis in shootings and bombings in 32 months of fighting. Abbas has been trying to negotiate with the militias rather than use force.

But on Friday Hamas said it was cutting off talks in retaliation for Abbas' concessions at a summit Wednesday in Jordan. At the meeting with President Bush and Sharon, Abbas called for an end to the "armed intefadeh."

Palestinian Information Minister Nabil Amr, speaking before a Palestinian Cabinet meeting Saturday, urged Hamas to return to the negotiations and give Abbas a chance to defend his actions at the summit.

"The only way to resolve the issue ... is through dialogue and whoever leaves the negotiating table is the loser," Amr said.

The Palestinian Parliament plans to hold a special session soon to hear a report from Abbas on the latest developments, Amr said.

Palestinian Foreign Minister Nabil Shaath said Abbas would never use force against Hamas and risk civil war, meaning Hamas' decision could derail the peace plan.

"We either reach a voluntary cease-fire ... or there will be no deal with Israel or road map," Shaath said in an interview with Future TV, based in Lebanon. "Our friends in Hamas and Jihad should acknowledge this and act responsibly."

Shaath accused Hamas leaders of jumping the gun by pulling out of the talks before Abbas could meet with them to explain what happened in closed meetings at the summit.

"They listened to the speeches on television and declared their decision to stop the dialogue and stop listening," he said.

Hamas officials simply were taking advantage of some Palestinian disappointment with Abbas' speech, Shaath said. After Hamas' decision to withdraw from the talks, thousands of supporters of the militant group rallied Friday to protest the summit.

Palestinian officials say the Hamas walkout may not be final and there's still a chance for a truce. Hamas, known for its pragmatism, would not risk a confrontation with security forces and would quickly resume talks, they said.

Officials in Washington said they were not surprised that Hamas, which is vehemently opposed to peace with Israel, broke off the talks.

Other efforts to clear the streets of gunmen continued, with Palestinian security chief Mohammed Dahlan offering to buy illegal weapons carried by members of the Al Aqsa Martyrs' Brigades, a militia linked to Abbas' Fatah movement, according to several Palestinian officials and militia members. The buyback was to start in the coming days, they said.

On Saturday, Dahlan denied such a program existed: "This is absolutely untrue."